Abstract: Calamus L. (Palmae : Calamoideae) is the largest palm genus, with about 370 species in the world. China is the north verge of its natural distribution, 37 species and 26 varieties are reported in southwestern and southeastern China respectively. The high proportion of endemic species indicates that the natural distribution of Calamus shows intensely regional. Its flora of southwestern China distribution center is closely related to that of western Indo-Chinese Peninsula and South Asia, and the southeastern China distribution center is more closely related to that of eastern Indo-Chinese Peninsula.

Key words: Calamus